The Science of Hydration: Why We Feel Tired in Hot Weather

Have you been noticing by the early afternoon this week you’re more tired and sluggish? During the warmer months, it’s very common to feel exhausted, especially when we’ve not been keeping hydrated during the day.

This can quickly lead to an energy slump during the afternoon, having an impact on our productivity and work output. The body has to work a lot harder during the hot weather to stay cool, which is why it’s vital to increase fluid intake to sustain energy levels.

During the workday, it can be easy for hydration to take a backseat, but drinking enough fluids is vital for concentration, productivity and performance.

If you’re wondering why you feel so tired this week, keep reading to find out more and how to combat the afternoon slump.

Why Hot Weather Makes Your Body Work Harder

The body maintains a core temperature of around 37 degrees. When temperatures outside rise, blood vessels widen, which is called vasodilation.

This can cause us to sweat more, which is the body’s response to staying cool through evaporation. But increased sweating means more fluid loss throughout the day.

During warmer temperatures, your heart is also working harder to circulate blood and regulate temperature. No wonder you feel more tired!

How Much Water Loss is Too Much?

A loss of just 1-2% of body fluids can affect physical and mental performance. As a result, most of us become mildly dehydrated even before feeling thirsty.

They can be subtle, but there are common warning signs for dehydration such as:

• Thirst
• Dry mouth
• Dark yellow urine
• Dizziness
• Muscle cramps

How to Stay Hydrated at Work During Hot Weather

Keep a refillable water bottle with you at all times, and consider having water available in the office for staff who forget. It’s important to drink before you feel thirsty as dehydration can happen quickly.

Another way to keep hydration up is to incorporate water rich foods into your diet such as:

• Watermelon
• Cucumber
• Strawberries
• Oranges

This will help you feel refreshed during warmer weather and boost hydration levels, all while being a delicious snack.

It’s important that workplaces make adjustments to help staff feel cool. Alongside incorporating a water cooler, make sure staff are taking more breaks than usual to keep hydrated.

Common Hydration Myths to Avoid

As with most things, there are many myths around dehydration to be aware of.

Myth 1: Everyone Needs Eight Glasses a Day

Although it’s sound advice and meant well, most individuals will need to drink more than eight glasses of water a day. This especially applies to those doing regular exercise, or those working outside in hot conditions. Individual needs vary, so this should be taken with a pinch of salt.

Myth 2: Coffee Always Dehydrates You

Consuming caffeine in moderation still contributes to fluid intake, especially when opting for instant or black coffee, made with mostly water.

Myth 3: Thirst is the Best Indicator for Dehydration

Many people wrongly assume that if they aren’t thirsty, they must be hydrated. Thirst is often a late signal that your body needs more fluids.

Thirst can be an unreliable guide because it varies so much between individuals and situations.

Older adults, for example, gave a weaker thirst response, making them more prone to dehydration. Rather than waiting until you're thirsty, drink fluids regularly throughout the day.

All in all, hot weather increases sweating and fluid loss, but everyone’s needs are different. Fatigue is one of the earliest signs of dehydration, while thirst becomes second.

Drinking fluids regularly can help maintain energy levels. Water is best, but tea, coffee and fresh fruits high in water content can all contribute towards boosting your fluids.

Staying Hydrated at Work is Essential

Feeling tired during hot weather isn’t simply a sign you’re not good with heat, but is the body’s response to rising temperatures as it has to work harder to keep you cool.

By understanding the science behind dehydration, you can take steps to stay more hydrated, focused and energetic throughout the working day.

As well as stocking a wide range of water, we also stock soft drinks, tea and coffee to keep teams hydrated and refreshed throughout the working day.